Holocene climate variability in the winter rainfall zone of South Africa
We established a multi-proxy time series comprising analyses of major elements in bulk sediments, Sr and Nd isotopes, grain size of terrigenous fraction, and δ18O and δ13C in tests of Neogloboquadrina pachyderma (sinistral) from a marine sediment sequence recovered off the Orange River. The records...
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fttriple:oai:gotriple.eu:HcxmwxZNK3ylRgHpGuhjD 2023-05-15T13:38:12+02:00 Holocene climate variability in the winter rainfall zone of South Africa Weldeab, S. Stuut, J.-B. W. Schneider, R. R. Siebel, W. 2018-09-27 https://doi.org/10.5194/cp-9-2347-2013 https://cp.copernicus.org/articles/9/2347/2013/ en eng Copernicus Publications doi:10.5194/cp-9-2347-2013 10670/1.o68b17 1814-9324 1814-9332 https://cp.copernicus.org/articles/9/2347/2013/ undefined Geographica Helvetica - geography eISSN: 1814-9332 envir geo Text https://vocabularies.coar-repositories.org/resource_types/c_18cf/ Journal Article https://vocabularies.coar-repositories.org/resource_types/c_6501/ 2018 fttriple https://doi.org/10.5194/cp-9-2347-2013 2023-01-22T19:13:08Z We established a multi-proxy time series comprising analyses of major elements in bulk sediments, Sr and Nd isotopes, grain size of terrigenous fraction, and δ18O and δ13C in tests of Neogloboquadrina pachyderma (sinistral) from a marine sediment sequence recovered off the Orange River. The records reveal coherent patterns of variability that reflect changes in wind strength, precipitation over the river catchments, and upwelling of cold and nutrient-rich coastal waters off western South Africa. The wettest episode of the Holocene in the winter rainfall zone (WRZ) of South Africa occurred during the "Little Ice Age" (700–100 cal years BP) most likely in response to a northward shift of the austral westerlies. Wet phases and strengthened coastal water upwellings are companied by a decrease of Agulhas water leakage into the South Atlantic and a reduced dust incursion over Antarctica, as indicated in previous studies. A continuous aridification trend in the WRZ and a weakening of the southern Benguela Upwelling System (BUS) between 9000 and 5500 cal years BP parallel with increase of dust deposition over Antarctica and an enhanced leakage of warm Agulhas water into the eastern South Atlantic. The temporal relationship between precipitation changes in the WRZ, the thermal state of the coastal surface water, and leakage of warm water in the South Atlantic, and variation of dust incursion over Antarctica suggests a causal link that most likely was related to latitudinal shifts of the Southern Hemisphere westerlies. Our results of the mid-Holocene time interval may serve as an analogue to a possible long-term consequence of the current and future southward shift of the westerlies. Furthermore, warming of the coastal surface water as a result of warm Agulhas water incursion into the southern BUS may affect coastal fog formation. Article in Journal/Newspaper Antarc* Antarctica Neogloboquadrina pachyderma Unknown Austral Climate of the Past 9 5 2347 2364 |
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envir geo Weldeab, S. Stuut, J.-B. W. Schneider, R. R. Siebel, W. Holocene climate variability in the winter rainfall zone of South Africa |
topic_facet |
envir geo |
description |
We established a multi-proxy time series comprising analyses of major elements in bulk sediments, Sr and Nd isotopes, grain size of terrigenous fraction, and δ18O and δ13C in tests of Neogloboquadrina pachyderma (sinistral) from a marine sediment sequence recovered off the Orange River. The records reveal coherent patterns of variability that reflect changes in wind strength, precipitation over the river catchments, and upwelling of cold and nutrient-rich coastal waters off western South Africa. The wettest episode of the Holocene in the winter rainfall zone (WRZ) of South Africa occurred during the "Little Ice Age" (700–100 cal years BP) most likely in response to a northward shift of the austral westerlies. Wet phases and strengthened coastal water upwellings are companied by a decrease of Agulhas water leakage into the South Atlantic and a reduced dust incursion over Antarctica, as indicated in previous studies. A continuous aridification trend in the WRZ and a weakening of the southern Benguela Upwelling System (BUS) between 9000 and 5500 cal years BP parallel with increase of dust deposition over Antarctica and an enhanced leakage of warm Agulhas water into the eastern South Atlantic. The temporal relationship between precipitation changes in the WRZ, the thermal state of the coastal surface water, and leakage of warm water in the South Atlantic, and variation of dust incursion over Antarctica suggests a causal link that most likely was related to latitudinal shifts of the Southern Hemisphere westerlies. Our results of the mid-Holocene time interval may serve as an analogue to a possible long-term consequence of the current and future southward shift of the westerlies. Furthermore, warming of the coastal surface water as a result of warm Agulhas water incursion into the southern BUS may affect coastal fog formation. |
format |
Article in Journal/Newspaper |
author |
Weldeab, S. Stuut, J.-B. W. Schneider, R. R. Siebel, W. |
author_facet |
Weldeab, S. Stuut, J.-B. W. Schneider, R. R. Siebel, W. |
author_sort |
Weldeab, S. |
title |
Holocene climate variability in the winter rainfall zone of South Africa |
title_short |
Holocene climate variability in the winter rainfall zone of South Africa |
title_full |
Holocene climate variability in the winter rainfall zone of South Africa |
title_fullStr |
Holocene climate variability in the winter rainfall zone of South Africa |
title_full_unstemmed |
Holocene climate variability in the winter rainfall zone of South Africa |
title_sort |
holocene climate variability in the winter rainfall zone of south africa |
publisher |
Copernicus Publications |
publishDate |
2018 |
url |
https://doi.org/10.5194/cp-9-2347-2013 https://cp.copernicus.org/articles/9/2347/2013/ |
geographic |
Austral |
geographic_facet |
Austral |
genre |
Antarc* Antarctica Neogloboquadrina pachyderma |
genre_facet |
Antarc* Antarctica Neogloboquadrina pachyderma |
op_source |
Geographica Helvetica - geography eISSN: 1814-9332 |
op_relation |
doi:10.5194/cp-9-2347-2013 10670/1.o68b17 1814-9324 1814-9332 https://cp.copernicus.org/articles/9/2347/2013/ |
op_rights |
undefined |
op_doi |
https://doi.org/10.5194/cp-9-2347-2013 |
container_title |
Climate of the Past |
container_volume |
9 |
container_issue |
5 |
container_start_page |
2347 |
op_container_end_page |
2364 |
_version_ |
1766102494806540288 |